Quick connect device for fractrap and method

ABSTRACT

A quick connect device for connecting a plug to a setting tool includes a collet having a body and plural fingers; a first end of the collet is configured to be attached to a trapping mechanism associated with the setting tool; and a second end of the collet has the plural fingers, which are configured to be attached to the plug. The second end automatically connects to the plug by only pushing the second end onto the plug.

BACKGROUND Technical Field

Embodiments of the subject matter disclosed herein generally relate to a quick connect device that is used in a well for setting a plug, and more specifically, to a setting tool having a ball trap that is modified with the quick connect device to attach without screws to the plug for setting the plug in the well.

Discussion of the Background

After a well is drilled and cased, a fluid connection needs to be established between the bore of the casing and the formations outside the well. One or more perforation guns are used for this purpose, i.e., to make holes through the casing to establish the fluid connection between the bore and the formations. The perforation guns may be lowered into the well together with a setting tool, a plug, and a corresponding ball, which is shaped to seal a bore of the plug. The setting tool sets the plug at a desired level inside the well, the ball is moved into the bore of the plug to seal it, and then the perforating guns are fired to establish perforations into the casing, i.e., to achieve the fluid connection between the bore of the casing and the formations. A fracturing fluid is then pumped into the well and into the formations, through the perforations, to fracture the formations. Because of the plug and the ball that seals the bore of the plug, the fracturing fluid is forced through the perforations only in the current stage.

A typical setting tool/plug system 100 is illustrated in FIG. 1A and includes the setting tool 110 and the plug 130 and a setting kit 120 that connects the setting tool to the plug. The setting kit 120 includes, among other components, an internal sleeve 112 and an external sleeve 114, that encloses the internal sleeve 112. The plug 130 has a mandrel 132 that defines a bore 134. Various elements are distributed along the mandrel 132, for example, a top push ring 136, an upper slip ring 138, an upper wedge 140, a sealing element 142, a lower wedge 144, a lower slip ring 146, a bottom push ring 148, and a mule shoe 150. The top push ring 136 becomes in direct contact with the external sleeve 114 while the bottom push ring 148 is attached with screws 149 to the internal sleeve 112. When the setting tool is activated, the external sleeve presses through the external sleeve 114 of the setting kit against the top push ring while the internal sleeve of the setting tool holds still the bottom push ring, through the internal sleeve of the setting kit. The setting tool is typically activated by an explosive charge that causes a piston to be driven inside the setting tool. The movement of this piston is used for sliding one of the internal sleeve or the external sleeve relative to the other sleeve.

This opposite motion of the internal and external sleeves 112 and 114 makes the wedges 140 and 144 to push away, radially, the slip rings 138 and 146, to engage the casing (not shown) of the well while also compressing the sealing element 142. This motion results in the slip rings pressing strongly against the casing, which prevents, due to the high friction, the entire plug from slipping relative to the casing, and also results in the sealing element sealing the bore of the casing, and thus preventing a fluid from moving past the plug.

After the plug has been set, the internal sleeve of the setting kit breaks out from the bottom push ring and thus, the setting tool and the setting kit detaches from the plug, so that the setting tool together with the perforating guns can be removed from the well. The plug is left behind and seals the casing of the well at that location. Thus, a fracturing operation can now begin. After the current stage is perforated with the guns and fractured, the above noted operations are repeated to deploy a new plug, to insulate a new stage, and to perforate and fracture the new stage to further establish a fluid connection between the interior of the casing and the formations.

An alternative mode of coupling the setting tool to the plug is shown in FIG. 1B, where the setting kit 120 includes the external sleeve 114 and a trapping mechanism 116, which is attached to the internal sleeve 112, and the trapping mechanism 116 is attached with screws 149, to a proximal end of the mandrel 132, which means that the internal sleeve 112 does not extend all the way through the bore 134 of the mandrel as in the case shown in FIG. 1A. In this instance, the trapping mechanism 116 is attached to the mandrel 132. The trapping mechanism 116 includes a wing 118 for trapping a ball that might be present inside the internal sleeve. However, even for this case, screws 149 are used to connect the mandrel to the trapping mechanism or to the internal sleeve. The screws 149 are designed in both cases to break when a certain force is applied, which is selected to be larger than the force necessary to set the plug.

The operation of attaching the plug 130 to the setting tool 110 in the above cases may result in incorrectly attaching the plug to the setting kit 120, or failing to fully attach the plug to the setting kit as the holes that are made in the setting kit to receive the screws 149 wear off in time and cannot be reused. Thus, there is a need to have a novel way to connect a setting kit to a plug so that there is only one way to connect these elements, and also to avoid the presence of holes or screws for connecting these parts to each other to extend their useful life.

SUMMARY

According to an embodiment, there is a quick connect device for connecting a plug to a setting tool. The quick connect device includes a collet having a body and plural fingers, a first end of the collet is configured to be attached to a trapping mechanism associated with the setting tool, and a second end of the collet has the plural fingers, which are configured to be attached to the plug. The second end automatically connects to the plug by only pushing the second end onto the plug.

According to another embodiment, there is a system for connecting a plug to a setting tool with a quick connect device. The system includes the plug, which is configured to seal a bore of a casing in a well, and the quick connect device. The quick connect device has a collet that automatically engages and locks onto the plug by only pushing the collet onto the plug.

According to still another embodiment, there is a method for connecting a plug to a setting tool before being deployed in a well. The method includes providing a plug having a mandrel, the mandrel having a ring that extends around and away from the mandrel; attaching a trapping mechanism to a collet; attaching the collet to the ring of the plug by only pushing the collet onto the plug; sliding the trapping mechanism, while connected to the collet and the plug, inside an external sleeve of a setting kit; and rotating the plug to attach threads of the trapping mechanism to an internal sleeve of the setting tool.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate one or more embodiments and, together with the description, explain these embodiments. In the drawings:

FIG. 1A illustrates a traditional setting kit that is connected to a bottom of a plug with plural screws;

FIG. 1B illustrates a setting kit having a trapping mechanism that is connected to a top of a plug with plural screws;

FIG. 2 illustrates a system that uses a quick connect device to connect the setting tool to a plug with no screws;

FIG. 3 illustrates the quick connect device having a sloped body that automatically connects to a ring of the plug by only pushing the quick connect device onto the plug;

FIG. 4A illustrates a plug that has a groove in which the ring is placed for being connected to the quick connect device;

FIG. 4B illustrates the ring being made of two parts that connect to each other with male/female features;

FIG. 5 illustrates a plug that has the ring formed integrally with a mandrel of the plug for being connected to the quick connect device;

FIG. 6 illustrates the quick connect device having a cylindrical body that automatically connects to a ring of the plug by only pushing the quick connect device onto the plug;

FIG. 7 illustrates a plug that has a groove in which the ring is placed for being connected to the quick connect device;

FIG. 8 illustrates the quick connect device having a collet with plural fingers, and one finger is longer that the others for engaging a dedicated slot into the plug; and

FIG. 9 is a flow chart of a method for attaching the setting tool to the plug with the quick connect device.

DETAILED DESCRIPTION

The following description of the embodiments refers to the accompanying drawings. The same reference numbers in different drawings identify the same or similar elements. The following detailed description does not limit the invention. Instead, the scope of the invention is defined by the appended claims. The following embodiments are discussed, for simplicity, with regard to a quick connect device that attaches a setting tool having a trapping mechanism to a plug. However, the embodiments discussed herein are applicable to any tool that needs to be attached to another tool, in a well, with no screws.

Reference throughout the specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with an embodiment is included in at least one embodiment of the subject matter disclosed. Thus, the appearance of the phrases “in one embodiment” or “in an embodiment” in various places throughout the specification is not necessarily referring to the same embodiment. Further, the particular features, structures or characteristics may be combined in any suitable manner in one or more embodiments.

According to an embodiment, a quick connect device for attaching a plug to a trapping mechanism of a setting tool includes a collet having a thread at one end and plural fingers at an opposite end. The threaded end connects to the setting tool or to the trapping mechanism of the setting tool while the plural fingers connect to the plug. No screws are used for these connections and thus, no holes need to be made either in the plug or in the trapping mechanism for this purpose. The collet automatically connects to the plug by pushing the collet onto the plug. The quick connect device and the trapping mechanism may be used with any existing setting tool. In one embodiment, which is discussed next, a so called FracTrap trapping mechanism (see, for example, U.S. Pat. Nos. 9,617,816, 9,464,499, 9,765,590) is taken as an example of a setting kit that is attached to the setting tool. A FracTrap trapping mechanism is different from a traditional setting kit in the sense that the trapping mechanism 116 (see FIG. 1B) is provided inside an external sleeve, to trap the ball that seals the mandrel of the plug. The plug used in this embodiment is a fracturing plug, also called a frac plug. However, other plugs may also be used with the discussed quick connect device.

According to the embodiment shown in FIG. 2, a quick connect device 210 is provided between a trapping mechanism 116 associated with a setting tool 220, and a plug 230 for achieving a mechanical connection between these elements. FIG. 2 shows such a system 200 in which the quick connect device 210 has the trapping mechanism 116 and the quick connect device 210 fully located inside the external sleeve 314, which is attached to the setting tool 220, and for this reason the trapping mechanism 116 and the quick connect device 210 are shown with a dash line. In one embodiment, the external sleeve 314 and the trapping mechanism 116 form a setting kit. As noted above, the setting tool 220 may be any known setting tool. For simplicity of explanation, the setting tool 220 in this embodiment is considered to have the internal and external sleeves shown in FIGS. 1A and 1B. However, the plug 230 is modified to be different from the plug 130 previously shown, as discussed later.

FIG. 3 shows in more detail one possible implementation of the quick connect device 210 and its functional relationships to the setting tool 220 (more precisely, to the internal sleeve 222 and the external sleeve 224 of the setting tool), the trapping mechanism 116, the external sleeve 314, and the plug 230. While the external elements of the plug 230 may be similar to those of the plug shown in FIGS. 1A and 1B, its internal mandrel 232 is configured to have a head portion 232A, which is proximal to the quick connect device 210, and is differently configurated form the head of the mandrel 132. More specifically, as shown in FIGS. 3 and 4A, the head 232A of the mandrel 232 has, in one application, a ring 234 formed around an entirety of the head. The ring 234 may be formed of various materials, e.g., metal, plastic, elastomer, etc. In one application, as shown in FIG. 4A, the ring 234 is manufactured separately from the plug 230. A corresponding trench 236 (see FIG. 4A) is formed in the head 232A of the mandrel 232 and the ring 234 is placed, partially, as shown in the figure, inside the trench 236. In one application, the ring 234 may be made from two or more parts 234A and 234B, as shown in FIG. 4B. The two parts may be formed to have male 410 and female 412 features that fit into each other so that the two halves 234A and 234B shows in the figure can lock together. More than two parts may be used to form the ring 234. The ring may be formed of the same material as the mandrel 232 or a different material.

Alternatively, as shown in FIG. 5, the ring 234 may be made integrally with the head 232A of the mandrel 232, i.e., to have a monolithic structure. This means that both the mandrel 232 and the ring 234 are made of the same material, for example, during the same manufacturing process, and there is no trench or groove 236. If the mandrel 232 is made of a composite material, the ring 234 may be made by over-molding during the manufacturing of the mandrel. Any other process may be used for forming the ring 234 on the mandrel 232. It is noted that irrespective of the implementation of the ring 234 on the mandrel 232, the ring 234 is designed to not slide relative to the mandrel 232. However, the ring 234 is designed to break at a certain force, for example, 10,000 psi, to release the quick connect device 230, as discussed later.

The connection between the quick connect device 210 and the plug 230 is now discussed with regard to FIGS. 3 to 5. These figures show the quick connect device 210 including a collet 214. The collet 214, as shown in FIG. 3, is configured to have threads 213 at a first end 214A, that are configured to fit corresponding threads of the trapping mechanism 116 of the setting tool 220. Thus, the collet 214 is attached to the trapping mechanism 116 of the setting tool 220. The collet 214 may have an internal bore 216 that allows a ball 310 to pass through. The ball 310 is hold in place in an internal chamber 119 inside the trapping mechanism 116. The ball 310 is sized to fit and close the bore 238 of the mandrel 232, after passing through the bore 216 of the collet 214. In other words, as shown in FIG. 3, an interior shoulder 240 of the mandrel 232 is sized to receive the ball 310, and to form a seat that together with the ball 310 seals the bore 238. However, the seat/shoulder 240 is sized to not let the ball 310 pass through the mandrel 232. Returning to the internal chamber 119, it has one or more openings 218 for allowing a fluid to enter into or to exit freely from the chamber.

The collet 214 is illustrated in more detail in FIGS. 4A and 5 and has a body 400 that includes threads 402 at a first end 214A, to connect to the threads 213 of the trapping mechanism 116 of the setting tool 220. The body 400 is shaped to increase in diameter from the first end 214A towards a second end 214B, i.e., to have a sloped side 420. The other end 214B of the collet 214 is shaped to have plural fingers 402-I, which are separated by each other by a corresponding gap G. Each finger 402-1 may have a corresponding tab 404-1, as shown in FIGS. 4A and 5, and the tab is configured to engage the ring 234 so that the collet 214 is fixedly and securely attached to the mandrel 232 of the plug 230 by simply pushing the collet onto the plug, over the ring 234. Because the body of the collet is made with a slope 420, the fingers 402-I may inherit the same slope. The collet may be made of any material. In one application, the collet is made of such a material that the fingers are flexible, i.e., when the tabs of the fingers engage the ring, the fingers bent upwards to embrace the ring of the mandrel. Note that FIGS. 4A and 5 show only two fingers 402-1 and 402-2 with their corresponding tabs 404-1 and 404-2 being engaged to the ring 234. However, in one application, all the fingers have corresponding tabs and each tab engages the ring 234.

The tabs and/or the ring are shaped and their material is selected in such a way so that a desired maximum force can be applied by the collet on the mandrel. If the force applied by the setting tool to the mandrel through the collet becomes larger than the desired maximum force, the ring 234 is designed to break and to release the tabs 404, so that the collet 214 can separate from the plug 230, the plug 230 remains set in place, and the setting tool 220 with the trapping mechanism 116 and the collet 214 can be retrieved from the well. In one application, the ring is exclusively part of the plug and the collet does not even directly contact or touch the plug, only the ring. FIGS. 6 and 7 show another implementation of the quick connect device 210, in which the collet 214 has no sloped sides, i.e., its body is cylindrical. All the other elements of this implementation are similar to those shown in FIGS. 3 to 5 and thus, their description is omitted herein.

Due to the fingers 402-I having the tabs 404-I on the quick connect device 210, and the ring 234 on the plug 230, there are no holes made either in the mandrel of the plug or in the internal sleeve or the trapping mechanism of the setting kit for attaching these elements to each other. After the setting tool 220 sets the plug 230, just the ring 234 of the plug 230 is broken, no other component. This means that as soon as the setting tool 220, the trapping mechanism 116, the external sleeve 314, and the quick connect device 210 are brought to the surface, there is no need to remove any screw, but simply a new plug 230 is attached to the collet 214 so that the tabs 404-I of the collet engage the ring 234 of the new plug and the connection between the plug and the setting tool is established. Because of this simplified connection process, the operator of the setting tool and plug cannot misconnect these elements with the trapping mechanism as they cannot be connected in any other way. Also, the multiple use of the setting tool, the trapping mechanism, the external sleeve, and the quick connect device do not damage any of their components, as only the ring of the plug 230 is damaged in the process. Therefore, as long as a new plug 230 is provided, the system 200 can be used multiple times with the same setting tool and quick connect device.

In one embodiment, which is illustrated in FIG. 8, one finger 402-3 has in addition to the corresponding tab 404-3, an extension 406-3, which is monolithically formed with the finger 402-3. The extension 406-3 makes the finger 402-3 to be longer than all other fingers 402-I. A corresponding longer slot 233 is formed in the head 232A of the mandrel 232, to accommodate this extension. This means that when the operator of the setting tool connects the plug 230 to the collet 214, the plug needs to be rotated so that the longer slot 233 matches and receives the extension 406-3 of the finger 402-3. Therefore, the plug can be added to the collet only if their angular orientations are aligned, i.e., the longer slot 233 acts as a key. In this way, after the collet is mechanically connected to the plug, the plug and the collet rotate as a single element, i.e., the plug cannot rotate relative to the collet. This feature ensures that the collet 214 also rotates with the plug, and thus, when the collet 214 is attached to the trapping mechanism 116 of the setting tool 220, these elements rotate in unison. In this respect, note that the collet 214 is fully disposed inside the external sleeve 314 and thus, it cannot be directly attached to the internal sleeve 112 unless it is connected to the plug 230. In other words, it is much easier to attach the collet to the plug and then the connected elements are passed through the external sleeve 314 of the setting kit, which is already attached to the setting tool, to connect the collar to the trapping mechanism. In one application, it is possible to connect the collar to the plug and to the trapping mechanism and then to slide these connected elements to the internal sleeve of the setting tool. While FIG. 8 shows the sloped collet 214, the same configuration can be implemented for the non-slopped collet.

In another embodiment, the quick connect device may use a reversed tabbed collet where the tabs stick outward rather than inward and thus the collet bends in instead of out, i.e., the tabs and the fingers enter inside the mandrel to engage the ring or a corresponding structure, for example, a trench. Also, a spring and ball bearing connection can be used in one application to connect the collet to the plug. A connection via a J-lock could also work to hook up a setting adapter to a frac plug to be set in the well.

The above discussed systems prevent any deviation from a standard procedure of assembly of the setting tool to a plug, at the well site. This approach reduces misruns due to the assembly at the well site where screws can be left out of the plug, thus causing a low set force and improper seal between the plug and the casing of the well. In one application, the system 200 is faster and easier to assemble, leaves less hard metal in the well, as all that is left behind is a thin soft metal ring. In yet another application, the system 200 improves the tool life and longevity of the tool with replaceable collet. The two piece shear ring shown in FIG. 4B overcomes the challenge of having a single shear ring over molded in a large horizontal mold.

A method for attaching the plug to a setting tool is now discussed with regard to FIG. 9. The method includes a step 900 of providing a plug 230 having a mandrel 232, the mandrel 232 having a ring 234 that extends around and away from the mandrel 232, a step 902 of attaching a trapping mechanism 116 to a collet 214, a step 904 of attaching the collet 214 to the ring 234 of the plug 230 by only pushing the collet 214 onto the plug 230, a step 906 of sliding the connected collet 214 and the plug 230, inside an external sleeve 314 of a setting kit, to contact an internal sleeve 222 of the setting tool 220, and a step 908 of rotating the plug 230 to attach threads of the trapping mechanism 116 to the internal sleeve 222 of the setting tool 220.

The disclosed embodiments provide methods and systems for connecting a plug to a setting tool having a trapping mechanism, without the use of screws. It should be understood that this description is not intended to limit the invention. On the contrary, the exemplary embodiments are intended to cover alternatives, modifications and equivalents, which are included in the spirit and scope of the invention as defined by the appended claims. Further, in the detailed description of the exemplary embodiments, numerous specific details are set forth in order to provide a comprehensive understanding of the claimed invention. However, one skilled in the art would understand that various embodiments may be practiced without such specific details.

Although the features and elements of the present exemplary embodiments are described in the embodiments in particular combinations, each feature or element can be used alone without the other features and elements of the embodiments or in various combinations with or without other features and elements disclosed herein.

This written description uses examples of the subject matter disclosed to enable any person skilled in the art to practice the same, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the subject matter is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims. 

What is claimed is:
 1. A quick connect device for connecting a plug to a setting tool, the quick connect device comprising: a collet having a body and plural fingers; a first end of the collet is configured to be attached to a trapping mechanism associated with the setting tool; and a second end of the collet has the plural fingers, which are configured to be attached to the plug, wherein the second end automatically connects to the plug by only pushing the second end onto the plug.
 2. The quick connect device of claim 1, wherein each finger of the plural fingers engages a ring located on the plug.
 3. The quick connect device of claim 2, wherein each finger has a tab which is configured to move past the ring and lock the tab onto the ring.
 4. The quick connect device of claim 3, wherein at least one finger of the plural fingers has an extension that extends past the corresponding tab.
 5. The quick connect device of claim 2, wherein at least one finger of the plural fingers is longer than the plural fingers.
 6. The quick connect device of claim 1, wherein the collet is attached with threads to the trapping mechanism.
 7. The quick connect device of claim 6, wherein the trapping mechanism is attached with threads to the internal sleeve of the setting tool.
 8. The quick connect device of claim 1, wherein the collet, the trapping mechanism, and the plug fluidly communicate with each other and a ball is sized to pass through the collet, from the plug to the trapping mechanism.
 9. The quick connect device of claim 8, further comprising: the ball, wherein the ball is sized to not pass through an internal bore of the plug and the trapping mechanism is configured to trap the ball to prevent the ball from returning to the plug.
 10. A system for connecting a plug to a setting tool with a quick connect device, the system comprising: the plug, which is configured to seal a bore of a casing in a well; and the quick connect device, wherein the quick connect device has a collet that automatically engages and locks onto the plug by only pushing the collet onto the plug.
 11. The system of claim 10, further comprising: a trapping mechanism configured to be attached to an internal sleeve of the setting tool; and an external sleeve configured to house the trapping mechanism and the quick connect device, wherein the collet is configured to be attached with a first end to the trapping mechanism and with a second end to the plug.
 12. The system of claim 10, wherein the plug has a mandrel and a ring located on the mandrel.
 13. The system of claim 12, wherein the collet has plural fingers at the second end, and each finger engages the ring located on the mandrel.
 14. The system of claim 13, wherein each finger has a tab which is configured to move past the ring and lock the tab onto the ring.
 15. The system of claim 12, wherein the ring is configured to break at a desired force, to free the quick connect device from the plug.
 16. The system of claim 12, wherein the ring is molded into a mandrel of the plug.
 17. The system of claim 12, wherein the ring is placed into a trench formed in a mandrel of the plug.
 18. The system of claim 13, wherein at least one finger of the plural fingers has an extension that extends past the corresponding tab.
 19. The system of claim 11, further comprising: a ball, wherein the trapping mechanism has an internal chamber configured to hold the ball and the ball is sized to pass through an internal bore of the collet.
 20. A method for connecting a plug to a setting tool before being deployed in a well, the method comprising: providing a plug having a mandrel, the mandrel having a ring that extends around and away from the mandrel; attaching a trapping mechanism to a collet; attaching the collet to the ring of the plug by only pushing the collet onto the plug; sliding the trapping mechanism, while connected to the collet and the plug, inside an external sleeve of a setting kit; and rotating the plug to attach threads of the trapping mechanism to an internal sleeve of the setting tool. 